This invention relates generally to refrigerators, and more particularly, to a temperature controlled compartment disposed in the refrigerators.
Temperature controlled compartments are typically cooled by, but are not limited to, a simple vapor compression cycle. The simple vapor compression cycle typically includes a compressor, a condenser, an expansion device, and an evaporator connected in series and charged with a refrigerant. The evaporator is a specific type of heat exchanger that transfers heat from air passing over the evaporator to refrigerant flowing through the evaporator, thereby causing the refrigerant to vaporize. The cooled air is then used to refrigerate one or more freezer or fresh food compartments.
Household refrigerators typically operate on a simple vapor compression cycle. Such a cycle typically includes a compressor, a condenser, an expansion device, and an evaporator connected in series and charged with a refrigerant. The evaporator is a specific type of heat exchanger that transfers heat from air passing over the evaporator to refrigerant flowing through the evaporator, thereby causing the refrigerant to vaporize. The cooled air is then used to refrigerate one or more freezer or fresh food compartments.
Household refrigerators are expected to operate over a range of ambient temperatures, typically from about 55xc2x0 F. to about 90xc2x0 F. System users are typically supplied control knobs to adjust Fresh Food and Freezer compartment temperatures. At each combined setting of the control knobs, there is a target set of Fresh Food and Freezer temperatures that an ideal refrigerator should achieve, independent of ambient conditions. Different hardware and control strategies attempt to approximate this ideal performance matrix.
Typically, a control device is used to regulate airflow to the fresh food compartment to account for the changing load split between freezer and fresh food sections. During high ambient temperature and frequent fresh food access, more airflow to the fresh food section is required to maintain target temperatures. Manual damper air control cannot automatically compensate for changing loads and is prone to customer misadjustment. Motorized damper airflow modulation, powered by a system controller, is prone to malfunction (i.e. freeze up) and may cause adverse temperature gradients during low ambient operation.
Accordingly, there is a need in the art for an improved refrigeration system for achieving ideal performance temperatures of temperature controlled compartments.
A temperature controlled apparatus comprises a reversible solid state device having a first section and a second section; portions of the first and the second sections are disposed in intimate contact. The first section is disposed adjacent to a portion of an external wall surface of a compartment and the second section is disposed adjacent to a portion of an internal wall surface of the compartment. A compartment fan is disposed within the compartment. The reversible solid state device and the compartment fan are coupled to a controller. The controller is configured to modify a compartment air temperature inside the compartment by controlling the reversible solid state device and the compartment fan to flow a compartment air across the second section. The controller is configured to control the reversible solid state device and the compartment fan in at least one temperature operational mode.